A188187 a(n) = [nr]-[kr]-[nr-kr], where r=sqrt(5), k=1, [ ]=floor.

0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1

Offset

1

Comments

See A188014.

Links

Table of n, a(n) for n=1..149.

Formula

a(n) = [nr]-[r]-[nr-r], where r=sqrt(5).

Mathematica

r=5^(1/2)); k=1;
t=Table[Floor[n*r]-Floor[(n-k)*r]-Floor[k*r], {n, 1, 220}]   (*A188187*)
Flatten[Position[t, 0]]  (*A188188*)
Flatten[Position[t, 1]]  (*A004958*)

Prog

(Python)
from sympy import integer_nthroot
def A188187(n): return integer_nthroot(5*n**2, 2)[0]-integer_nthroot(5*(n-1)**2, 2)[0]-2 # Chai Wah Wu, Mar 16 2021

Crossrefs

Cf. A188014, A188188, A004958.

Sequence in context: A353813 A353814 A144596 * A341996 A341999 A118685

Adjacent sequences: A188184 A188185 A188186 * A188188 A188189 A188190

Keyword

nonn

Author

Clark Kimberling, Mar 23 2011

Status

approved